Polytunnels have proved to be very hardy in their relatively short life as garden buildings. Many people worried that they would act like tents and be carried away by the first strong wind but that hasn’t been the case.
Get the Correct Grade Cover
Of course a polytunnel is not as sturdy and long-lasting as a greenhouse; if they were they wouldn’t be so much cheaper. When you buy or make your polytunnel make sure the cover is at least 720 gauge (this equates to around 180 microns) which is the thickness used by commercial growers. A cover this thick is expected to last for about five years but they have been known to last for over ten years.
As with any other garden building the key is regular checking and maintenance so that problems are nipped in the bud. This is particularly true of rips or tears in the polythene cover, which are the most likely form of damage that a polytunnel will sustain.
Repairing a Tear With Tape
A tear can be repaired with tape available from the supplier of the polytunnel or polythene but the longer it is left the larger it will grow. If you are inspecting the cover regularly you will spot damage like this before it’s too late. When you repair a tear, run the tape along the length of the tear initially but then place tape at 90 degrees to the tear as well. This will strengthen the repair, and you could consider taping from both sides, inside and out.
You can, of course repair a tear in the polythene with any strong tape, even if it’s not clear, something like duct tape or carpet tape, for example. Of course you will lose a little light and it won’t look particularly good, but it will be better than nothing. But if at all possible you should get proper polythene repair tape. Look for ‘UV stabilised’ on the label as this means it will not go brittle under the sun’s rays.
Repairing At Each End
You should check the frame of your polytunnel as well as the cover, particular the door frames at the end, or battens if there is no door at one end. Check that the cover is properly fixed to this wood. With smaller domestic polytunnels the door and frame are often made of wood and the cover will be stuck or stapled to the wood. Look for areas where the cover is beginning to come away and re-fix it, using tape to cover the repair if necessary.
Checking Along the Frame of Hoops
Go along the polytunnel checking each hoop, running your eyes and fingers along each one from one side to the other. Make sure the anti-hot-spot tape is in good condition and is still separating the hoop from the cover. If it isn’t then heat build-up will weaken the cover at this spot, leading to premature failure and making repair necessary.
If you find a tear in the cover close to a frame component, don’t just repair it and walk away. Look for the cause of the tear and if it is a protruding sharp edge from a frame component, tape that up so that it covers the cause of the damage. It makes sense, because otherwise you will be having to make the same repair in a couple of months time.
You Polytunnel Will Reward Your Care
Take care with your polytunnel, give it regular inspections and repair faults quickly and it should reward you with many years of service. This is one garden building where the phrase ‘a stitch in time saves nine’ has never been more appropriate.